Composite Lay-up Gaps for Vacuum Bag Adaptation

Solution Overview

Problem

The existing lay-up methods for composite aircraft parts with openings like manholes or handholes require additional material for ramp geometry to facilitate vacuum bag fitting during curing, leading to material waste and increased costs.

Innovation Solution

Incorporating strategically located gaps within the composite tows, approximately 3/5 of the semi-major axis from the center, to allow for vacuum bag adaptation without the need for ramp material, reducing material usage and waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If extra material with ramp geometry is added to facilitate vacuum bag fitting, then vacuum bag adaptation is improved, but material waste and manufacturing cost increase

Engineering Contradiction:

Improvevacuum bag fittingVSAvoidmaterial waste

Core Design Contradiction:

Ease of operationVSLoss of substance

Solution Approach 1:

The opening perimeter is segmented into multiple discrete tow elements rather than using continuous extra material. Individual tows are positioned at specific locations (e.g., at 45-degree angles from the major axis) to provide vacuum bag adaptation points, eliminating the need for continuous ramp geometry and reducing material waste.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of adding extra material uniformly around the entire opening perimeter, the invention applies tow elements only at specific local positions where vacuum bag adaptation is most needed. This localized approach provides the necessary functionality while minimizing material usage and waste.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If extra material with ramp geometry is added to facilitate vacuum bag fitting, then vacuum bag adaptation is improved, but manufacturing cost increases

Engineering Contradiction:

Improvevacuum bag fittingVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The opening perimeter is segmented into multiple discrete tow elements rather than using continuous extra material. Individual tows are positioned at specific locations (e.g., at 45-degree angles from the major axis) to provide vacuum bag adaptation points, eliminating the need for continuous ramp geometry and reducing material waste.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of adding extra material uniformly around the entire opening perimeter, the invention applies tow elements only at specific local positions where vacuum bag adaptation is most needed. This localized approach provides the necessary functionality while minimizing material usage and waste.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If openings are laid-up in their entirety and then cut afterwards, then opening geometry precision is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveopening geometryVSAvoidmanufacturing process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The opening perimeter tows are pre-positioned and laid-up in their final correct positions during the initial lay-up process, rather than laying up extra material and cutting it later. This preliminary positioning ensures geometric precision while simplifying the manufacturing process by eliminating subsequent cutting operations.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP4344860B1Lay-up method of composite aircraft parts comprising an opening

Publication Date: 2025.01.15 AIRBUS OPERATIONS SL

Figure 1~2

AI summary

Lay-up method of composite aircraft parts comprising an opening, the method comprising the steps of laying-up composite tows (5) having an orientation of 0º, 90º or +/-45º forming plies which in turn form a composite laminate, wherein at least each tow (5) having an orientation of 0º and being within the perimeter (10) of the opening comprises: - a first gap (4) located at approximately 3/5 of the length of the first semi-major axis (9) from the center (3), the first gap (4) being configured as a first elongated gap longitudinally perpendicular to the orientation of the tow (5), and - a second gap (7) located at approximately 3/5 of the length of the second semi-major axis (9) from the center (3), the second gap (7) being configured as a second elongated gap longitudinally perpendicular to the orientation of the tow (5).